Abstract
Purpose :
The pathogenesis of pterygium is well-studied using human pterygium epithelial cells (hPEC), however, it is still unclear in mouse experimental model. As part of our ongoing effort to develop mouse experimental model, we induced pterygium-like lesion in athymic nude mouse by hPEC subconjunctival injection. And we further identified pathological protein expression in the pterygium-like lesion of cornea.
Methods :
We induced pterygium in male athymic nude mouse (8 weeks, n=8) by nasal subconjunctival injection of hPEC (1×105 cells in 10 μL of DPBS). Cornea was observed by retinal microscopy with OCT and histochemistry. Cornea lesion was photographed with macroscopy for 10 days. Corneal thickness and lesion size were measured. Corneal neovascularization (NV) was scored from 0 through 3 where 0=no NV, 1=NV confined to the corneal periphery, 2=NV extending up to the pupil margin, and 3=NV extending beyond the pupil margin into the central cornea. Protein expression in cornea was analyzed by immunostaining and immunoblotting. Student’s t-test was used for statistical analysis.
Results :
For 10 days, pterygium-like lesion was increased in the hPEC-injected mouse. Pterygium-like lesion grew over the cornea in the hPEC-injected mouse. OCT photograph showed that corneal thickness was significantly increased in the lesion (235.3±22.1 μm), compared with normal cornea (163.1±14.8 μm). Corneal NV was extended into the central cornea and scored 2.1±0.6. Histochemistry figure showed neovascularization and macrophage infiltration in epithelial layer of cornea. Protein expressions of VEGF, ICAM-1, VCAM-1, fibronectin, MMP-2, and MMP-9 were increased in the lesion area. Pro-inflammatory cytokines including TNFα, IL-1β, and IL-6 were produced and co-localized with macrophage in the lesion area.
Conclusions :
Pterygium-like lesion in mouse cornea after hPEC injection showed similar clinical features of human pterygium. Furthermore, the lesion showed to increase protein expressions related with neovascularization and inflammation in cornea. The hPEC-injected athymic nude mouse may be a useful in vivo model for studying human pterygium.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.